<template>
    <div class="todo-footer" v-show="totoal">
        <label>
          <input type="checkbox" v-model="isAll"/>
        </label>
        <span>
          <span>已完成{{done}}</span> / 全部{{todos.length}}
        </span>
        <button class="btn btn-danger" @click="clearAll">清除已完成任务</button>
    </div>
</template>

<script>
export default {
    name:'FooterDown',
    props:['todos'],
    computed:{
        totoal(){
            return this.todos.length
        },
        done(){
            return this.todos.reduce((pre,current)=>pre+(current.done?1:0),0)
        },
        isAll:{
           get(){
                return this.done === this.totoal && this.totoal>0
           },
           set(value){
               this.$emit('checkAllTodo',value)
           }
        }
    },
    methods: {
        clearAll(){
            this.$emit('clearAllTodo')
        }
    },
}
</script>

<style>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}

</style>

